Highly diastereoselective oxa-[3+3] cyclization with C,N-cyclic azomethine imines <i>via</i> the copper-catalyzed aerobic oxygenated CC bond of indoles
Herein, a copper-catalyzedhighlydiastereoselective aerobic oxygenated [3+3] cyclization of 3-substituted indoles with C,N-cyclic azomethine imines using oxygen as the sole oxidant under mild conditions has been developed. This protocol provides a simple and convenient approach for constructing [2,3]-fused indoline O-heterocycles bearing two pharmaceutically intriguing parts, tetrahydroisoquinoline